Posted by Darrell Nicholson at 02:17PM - Comments: (9)
When awakening your boat from its winter slumber a rig check should be high on the list of priorities. Even though the boat has been sitting still, the laws of physics still take their toll. Corrosion is the biggest enemy and the stainless steel components in your rig can effectively hide the insidious advance of this disease. "The Hidden Causes Of Rig Failure," in the May 2015 issue of Practical Sailor offers a bit of a wake-up call for owners of sailboats with rigs of an indeterminate age. But it also offers some of hope. Over the years we’ve published a variety of articles on the hidden risks of stainless-steel hardware—chainplates, tangs, toggles, clevis pins, etc.—important bits that keep our rig from coming down.
Probably the most detailed article on the topic was technical editor Ralph Naranjo’s critique of stainless steel (see Practical Sailor, February 2007 online). Patrick Childress concentrated on chainplate problems, which was behind the causes of his mid-Pacific rig failure (see Practical Sailor, December 2011 online). And various installments of Mailport and PS Advisor have featured readers' experiences with hardware such as snap shackles (See PS Mailport April 2010 online) and questions regarding rigging replacement schedules (see PS Advisor January 2010).
One underlying moral of these stories is that stainless steel can fail without warning, a message that can leave a boat owner feeling helpless. Does this mean that our only resort is to replace anything that raises suspicion? The line between caution and paranoia becomes thin. Fortunately, stainless steel hardware has a long and mostly successful track record on boats, and the warning signs are often apparent. The trick is knowing where to look.
Boat owners can turn to a number of helpful resources that will guide them through an inspection to ensure that their rigs are up to snuff. If your boat was built in the last decade or so, chances are that the boat manufacturer, or the spar company contracted to supply the rig includes service and inspection guidance. For owners of older boats, owners’ associations can be a vital source. Websites or bulletin boards dedicated to Taiwan builders such as Hans Christian, Ta Chiao (Formosa, Island Traders, CT) and Tayana, as well as many U.S.-built boats (like Childress’ Valiant 40) have documented a range of chainplate problems and repairs in detail. Some of these are quite obvious, and will usually turn up in a routine visual inspection, others are not. (Google-search under your boat model and chainplate, for example “Tayana 37 chainplate,” to see what sort of history your boat might have.)
The U.S. Coast Guard Marine Safety Alert, “Sailboat Rigging Dangers,” issued in 2009, has links to a couple of helpful websites. The alert, which was published after a spate of rigging failures on Coast Guard-certified charter catamarans, should be required reading for every sailor, whether he has questions about the integrity of his rig or not.
In the upcoming May issue of Practical Sailor, renowned rigger and sailing writer Brion Toss, explores of rigging failure in finer detail in an excerpt from his forthcoming book, “Rig Your Boat.” Here are just some of the tips that Toss shares.
- Follow the load. Follow the path that loads on your rig follow as they are transferred to the hull or deck. Sharp bends, and slack, ill-fitting, or misaligned unions will concentrate loads in one area and increase the chance of failure at these points. Seemingly minor oversights like using an undersized clevis pin on a toggle can lead to premature failure.
- Beware of hidden dangers. Many failure points are often physically hidden from view. Crevice corrosion in chainplates, bobstays, and padeyes often starts where the stainless comes into contact with wet wood or core material, or in fiberglass laminate where water has been trapped. The corrosion is often located on the bottom or back side of the hardware, or buried where the fitting passes through the hull or deck. Seemingly innocuous blooms of rust are often a sign of more serious corrosion is hidden in the hull or deck.
- Go aloft. If you don’t unstep your mast each season, you or a qualified rigger should go aloft at least once a year to inspect wire, terminals, spreaders, and the hardware and fittings at the top of your mast. You should hire a pro to do a full inspection every six years, and start thinking about wire replacement after 10-12 years—although this can vary greatly according to use and environmental factors. While you’re off the ground, check around mast tangs for signs of slipping. On painted masts, an exposed unpainted area is often a sign that a tang is slipping. Lower swages (see below) are often cited as the most common source of rig failure, but because these are easy to rinse at the dock, they are often in better shape that the upper-level swages.
- Inspect swages. Deck-level wire swages are one of the most common sources of failure on saltwater cruisers. Cracks, swelling, or weeping rust stains are a sign that time is running out for this hardware. Although no absolute timetable exists, riggers we have spoken with advise owners to start thinking about wire replacement after 10-12 years.
- Read the instructions. Turnbuckles can only be loosened so far; screw-on Norseman-type terminal fittings need to be correctly assembled and sealed. Neglecting to review the installation guidelines for any component in your rig is asking for trouble.
Bottom line: Some of the so-called hidden dangers of stainless steel hardware and rigging are not so hidden after all, but we need to know what to look for.
If you know of a good source of information on rig maintenance and inspection that you’d like to share, or specific problems that you’ve found on your own boat, drop us an email at email@example.com.
Here is one from Selden that several readers have found helpful:
For more rig inspection tips, check out "The Hidden Causes Of Rig Failure," in the May 2015 issue of Practical Sailor.